Propulsion Is Possible

Note: Production of the Zipp sub9 disc ended in June 2013. Zipp will continue to provide ongoing support for this product through our normal sales/service channels.

See the Zipp Super-9 as an alternative disc.

The Sub-9’s highlights so far include a pair of Ironman® 70.3 World Championships, a Tour de France® yellow jersey and some of the fastest Ironman®-distance bike splits ever recorded. We expected nothing less from the ultimate aerodynamic breakthrough.

In the center of the aero “sweet spot” – a wind angle of 12 to 18 degrees – the Zipp® Sub-9 was the first wheel ever to produce forward lift, when paired with our 21 mm Tangente tire. To achieve this feat, we added a toroidal bulge similar to our spoked rims around the edge of the disc to control airflow at the wheel’s leading and trailing edges. In addition to improving aero performance, the bulge’s vertical compliance keeps the Sub-9 glued to the road when cornering and yields a comfortable ride, hour after hour. This makes it the ideal choice for long-course triathletes to bounce out of Transition 2 for the run with fresh legs after a blistering bike split.

For decades, an obsession with aerodynamics has influenced everything from wheels to water bottles. But with the Sub-9 disc, we moved from minimizing drag to maximizing propulsion.

The Sub-9 may present some fitment issues for a small number of frames. The clearance between the chainstay and the rim may not be adequate to avoid contact between each other when ridden under load. We urge customers who plan on riding the Sub-9 to test the wheel within a frame under riding roads and conditions before purchasing. Clearance within individual frames of the same size, from the same manufacturer, may vary. Customers who run into this fitment issue may consider Zipp’s Super-9 or 900 discs as alternatives. Below is a list of known frames that may present this issue. This list will be updated if this fitment issue is discovered elsewhere.

Advanced Boundary Layer Control (ABLC) refers to the patented and instantly recognizable dimpled pattern found on all of our carbon rims. ABLC smoothes airflow across the rim's surface and is tailored to every model from the 202 to the Super-9 Disc. The third-generation of ABLC has up to four times more dimples than before.

Visco-Elastic Constrained Layer Control (VCLC) uses a vibration-absorbing material sandwiched between layers of rigid carbon laminate in the rim. When the wheel receives an impact from the road, much of the shock is absorbed by the VCLC system, delivering a 10% reduction in vibration.

Carbon Bridge uses a Kevlar® thread in a co-axial helix stitch to bind sheets of carbon to each other in our tubular rims. Because Kevlar is 350% more impact resistant than carbon, it can disperse shock more evenly throughout the carbon laminate, making for a rim that is practically bulletproof. In particular, Carbon Bridge reduces the vulnerability of the rim's tire bed, the area most susceptible to damage from impact.

Every aspect of our 88 and 188 hubs sets a new benchmark. The standard steel bearings are the roundest in the industry. The 17mm axle is the stiffest of any road hub we've tested. The wire EDM-cut hub internals are the most precise. When it comes to precision and performance, there's really no comparison.